Effect Of An Oil Water Separator's Shape On It's Effectiveness

The purpose of this experiment was to determine if the shape of an oil-water
separator affected how effectively it separated oil from water

I became interested in this idea when Mr. Norm Hepner, a department of ecology
professional engineer, informed me that some oil-water separators could be more
effective than others.

The information gained from this experiment will affect us all because if oil
mixes with wastewater it is a danger to everyone. It is people who own or
manage parking lots or carwashes who have the legal responsibility to make
their wastewater cleaner, but all of us are affected.

HYPOTHESIS

My hypothesis was that the circular shaped oil water separator would work
better because it has less dead space (places where the water sits in one spot)
so the oil would have less setting time in the primary chamber

I based my hypothesis on my understanding of fluid dynamic principles and oil
water chemistry (stoke’s law). Fluid dynamics are the characteristics of
how a fluid will act, this is also known as Fluid mechanics. Oil water
chemistry depends on something’s density and its viscosity. The density
is a measure of a quantity such as mass per unit volume, and the viscosity is
how thick or sticky something is. Stokes law is the formula showing the
velocity at which a less dense liquid will rise through a more dense
liquid.

EXPERIMENT DESIGN

The constants
in this study were:

Size of buckets

Temperature of water

Amount of water

Amount of oil

Type of oil

Rate at which mixture was poured in

Size of polypropylene pads

Polypropylene Pad absorbency

The manipulated variable was the shape of the oil-water separators.

The responding variable was how much oil was in the polypropylene at the end of
the experiment.

To measure the responding variable I used a scale to measure the change in mass
of the polypropylene pad after it had absorbed the oil.

MATERIALS

QUANTITY

ITEM DESCRIPTION

1

rectangular
7.5 liter bucket

1

rounded 7.5
liter bucket

4

gallons of
water

1

gallon of oil

6

pads of
polypropylene

2

nozzle

3

separate
buckets to mix oil and water in

1

drill

1

paint
stirring rod

1

caulking gun

2

tubes of
Epoxy

PROCEDURES

1. Build two separators

a) Find measurements of separators

b) Cut separator to required lengths

c) Put divider in bucket

d) Use epoxy to keep in bucket

e) Wait for epoxy to dry

f) Drill hole in side of bucket

g) Place plastic nozzle in separator

h) Put epoxy on nozzle to secure

i) Wait for epoxy to dry

j) Repeat steps A-I using other separator

2. Fill
Separator with clean water

3. Cut 6 polypropylene pads

4. Weigh all polypropylene pads

5. Weigh all Ziploc bags

6. Place 1 pad in each of the six bags

7. Weigh all bags containing pads

8. Pour .5 liters of oil into solution bucket

9. Pour 7 liters of water into solution bucket

10. Pour 7.5 liters of water into separator

11. Use paint stirring rod to mix solution

12. Open solution bucket valve

13. Open separator nozzle

14. Wait for solution bucket to empty

15. Close separator nozzle

16. Let it sit for 5 minutes

17. Place polypropylene pad in collection bucket

18. Stir around for 5 minutes

19. Take pad out of bucket

20. Hang up to dry

21. Wait 45 minutes

22. Place in Ziploc bag

23. Put rubber band around bag

24. Place on scale

25. Measure weight

26. Clean out all buckets and separators

27. Repeat steps 2-26 for trials 2 and 3

28. Repeat steps 2-27 using other separator

RESULTS

The original purpose of this experiment was to find if an oil water separator’s
shape affected the separator’s ability to do its job.

The results of the experiment were that
the square separator worked better than the circular separator, I know this
because the square had an average weight gain of 42.13 grams, where as the
circular separator had an average weight gain of 50.37. I think this was because the circular did not
have as much surface area causing the oil to go down deeper and letting it pass
through the separator.

CONCLUSION

My hypothesis was that the circular separator would work better because there
would be less dead spaces.

The results indicate that this hypothesis should be rejected because the square
separator was more effective than the circular.

Because of the results of this experiment, I wonder if varying the depth of the
separator would have any effect on how the oil water separator performs.

If I were to conduct this project again I would make the separators have the
same surface area to eliminate the possibility of that having an effect on the
experiment. I would also have more trials, and test lighter and heavier
types of oil.